Large capacity air flow fans for ventilation, house cooling and the like often utilize belt drives between the blade assembly and an electric motor to achieve quiet operation, proper fan blade rotational velocity and economy of manufacture.
Commonly, belt-driven ventilating fans include a tubular throat in which the blade assembly is located and the throat is associated with a shroud or housing for positioning the throat and mounting the motor and blade apparatus. Conventionally, the mounting structure for the motor and blade assembly includes U-shaped brackets attached to the fan structure in axial alignment with the throat, the U bracket configuration being necessary to provide the clearance and alignment required for the motor and fan blade structure.
The use of such U-shaped brackets adds considerable dimension to the complete fan assembly in the axial direction of the throat, and such axial length creates shipping problems and increased handling costs, as well as sometimes creating installation problems.
Various belt-driven fans are known which do not employ such U-shaped brackets, but known fan constructions which eliminate such brackets still have greater axial dimensions than is desired and such constructions do not achieve the economy of manufacture sought. Typical belt-driven fan devices of known types are shown in U.S. Pat. Nos. 2,332,552; 2,385,152; 2,485,356; 2,980,007 and 3,482,767.
It is an object of the invention to provide a belt-driven fan having a low profile in the axial direction of air movement wherein high air volumes can be achieved in a fan having a relatively small axial dimension.
A further object of the invention is to provide a belt-driven fan system utilizing a flat apron in conjunction with a tubular throat wherein support members for an electric motor are mounted on the apron substantially coplanar therewith and the same support members for the motor are used to mount the bearing structure for the blade assembly.
Another object of the invention is to provide a belt-driven fan assembly having a concise axial dimension and using an electric motor wherein the motor is mounted on a support bracket pivotal between operating and shipping positions, the shipping position of the motor bracket substantially reducing the axial dimension of the fan assembly and reducing handling costs.
In the practice of the invention the fan shroud includes a planar apron centrally intersected by a tubular throat. A pair of parallel linear angle iron support members are attached to the apron on opposite sides of the throat axis, and a bridge is disposed between the support members in alignment with the throat axis. A bearing housing mounted upon the bridge extends into the throat and includes a shaft upon which the blade assembly is mounted. Additionally, a cup-shaped pulley is mounted upon the blade shaft intermediate the bearing housing and the blade assembly.
A motor mounting bracket is also interposed between the support members adjacent the periphery of the apron. The motor bracket is adapted to receive an electric motor having a driveshaft and pulley which align with the blade shaft pulley when the motor bracket is in its operative position.
The motor bracket is removably bolted to the support members, and is of such a configuration that it may be pivoted relative to the support members to a shipping position locating the motor bracket within the confines of the support members, and locating the electric motor within the throat. In such a shipping position the axial dimension of the fan assembly is minimized to simplify boxing and crating, and minimizing shipping costs.
The components of the invention are primarily formed of sheet metal, and the arrangement of the support members, the mounting of the bearing housing for the blade assembly, and the alternate mounting of the motor bracket permits achievement of the objects of the invention without expensive fabrication techniques.